body {
	background-color: antiquewhite;
}
.content-box {
	box-sizing: content-box;
	margin: 100px;
	padding: 50px;
	border: 10px solid #66f;
	width: 80px;
	height: 80px;
	background-color: #f66;
}
.border-box {
	box-sizing: border-box;
	margin: 100px;
	padding: 50px;
	border: 10px solid #66f;
	width: 80px;
	height: 80px;
	background-color: #f66;
}
/* bfc */
.bfc-child1 {
	margin-bottom: 20px;
	width: 100px;
	height: 100px;
	background-color: aqua;
}
.bfc-child2 {
	margin-top: 30px;
	width: 100px;
	height: 100px;
	background-color: #66f;
}